Accessible Design of Electrospinning Device for N95 Compliant Filter Media

Our research aimed to develop a process for creating N95 compliant filter media that could be easily replicated in any community around the world. The main motivation for the project was the urgent need for personal protective equipment (PPE) throughout the medical industry and communities during the COVID-19 pandemic. Statistics show that even the use of fabric face coverings, with low-efficiency filtering, dramatically reduces the transmission of COVID-19. To significantly multiply the benefits of face coverings against COVID-19, a filter media can be formed by electrospinning a thin layer of polymer fibers onto a common fabric or mesh. In addition, air pollution accounts for an estimated 9% of deaths worldwide – 5 million people per year. If face covering filtration could be improved, the impact on human life in regions of high air pollution would be phenomenal.   To produce the membranes, a high voltage is applied to a metal needle, through which a solution is passed that contains a polymer dissolved in easily-evaporated solution. Under the needle, a conductive target is connected to ground. The electric field between the needle and the ground draws the solution rapidly towards the target, in a chaotic manner. As the solution evaporates, the polymer forms into thin fibers that spray over the surface of the conductive target. A layer of a substrate is placed on the conductive target which collects the accumulating fibers and is converted into a filter membrane.   Our method for optimizing the electrospinning process included the creation of a variable setup which allowed us to test multiple electrospinning heights, voltages, and solution flow rates. We researched various solvent and polymer combinations, drawing upon available literature and Hansen solubility parameters to determine ideal solutions and concentrations. We especially focused on solutions with relatively low toxicity and global availability to be produced in developing countries. We verified filtration efficacy in accordance with Occupational Health and Safety Administration testing standards through a TSI Portacount.   To date, we have devised a low cost, accessible electrospinning system designed for the developing world. This includes a CRT television power source, PVC pipe frame, and IV solution pump system. We identified solutions made from commonly available materials that performed well while electrospinning to form filter media. For example, one solution was composed of acetone, vinegar, and cigarette filters. These filter membranes provided filtration efficiencies greater than 99% for N95 particulate.    The successful production of this electrospinning apparatus demonstrates that countries with low resources or poor infrastructure may produce effective protective personal equipment without incurring excessive financial burden, without obtaining expensive equipment, and without toxic substances.